EF76 Nebulon-B escort frigate
The EF76 Nebulon-B escort frigate, a warship measuring 300 meters in length, was manufactured by Kuat Drive Yards. Initially, the Imperial Navy employed these vessels to safeguard their convoys, protecting them from attacks launched by Rebel Alliance starfighters. However, the Rebel Alliance became more well-known for its use of the frigate.
Characteristics
A typical Nebulon-B frigate was outfitted with a formidable arsenal: a dozen turbolasers, a dozen laser cannons, and a pair of tractor beam projectors. Its design also incorporated the capability to transport two dozen TIE Series starfighters.
Despite its generally strong armament for a ship of its dimensions, the spar that connected the midsection was a notable weak point. Concentrated fire from heavy weapons could split open this section, causing the ship to lose its atmosphere and resulting in mass casualties among the crew.
History

The EF76 entered service near the end of the Clone Wars as a ship designed for counterinsurgency operations. It largely replaced the Class-C frigate. The Nebulon-B's original purpose was to shield Imperial convoys from Rebel starfighter assaults, as the Imperial Navy was reluctant to dedicate its valuable Imperial-class Star Destroyers to escort duties. Furthermore, the CR90 corvettes were deemed too fragile and had limited capacity for carrying TIE fighters.
During the Galactic Civil War, both sides made extensive use of the EF76. It gained a reputation for its effectiveness against fighters and bombers. Its deployment in Imperial convoys to counter fighters had a significant impact, forcing the Rebels to re-evaluate their hyperspace raid tactics after suffering substantial losses of fighters and experienced pilots. These frigates often provided support to larger capital ships, such as Imperial-class Star Destroyers and Rebel Mon Calamari Star Cruisers.
Admirals Thrawn and Zaarin of the Imperial Navy sometimes chose Nebulon-B frigates as their command ships, instead of the more typical Star Destroyer.
Rebel usage
Before the Rebel Alliance was officially established, the Alderaanian Resistance forces, allied with Alya Aldrete and Bail Prestor Organa, utilized the escort frigate named Resurgence.

The Rebel Alliance also managed to obtain a number of these vessels through various means, including defections, battlefield captures, and outright theft. In fact, one of their initial flagships was a Nebulon-B that they seized during a battle over Ylesia, which they renamed the Salvation. The Rebels were not alone in acquiring Nebulon-B frigates outside of Imperial channels. Rumors circulated that Kuat Drive Yards discreetly sold these frigates to interested third parties through clandestine fronts, in order to avoid conflict with the Imperial Navy. The price for a frigate was 19,400,000 credits, which was said to be one-twentieth of the cost of an Imperial-class Star Destroyer. The Rebels' use of the Nebulon-B was so widespread that, during the Battle of Oovo IV, Imperial Admiral Hurkk expressed his frustration and requested that the Imperial fleet be allowed, for once, to destroy a Rebel starship that the Empire had not originally paid for.
The Rebels discovered additional applications for these ships, leveraging their advanced sensors and long-range multifrequency antennas. Escort frigates were used as scouts for long-range missions, search and rescue operations, and to transmit information to command ships during combat. In smaller, understaffed Rebel task forces, Nebulon-B frigates frequently functioned as command ships. One Nebulon-B, known as the Redemption, served as the Alliance's primary hospital ship.
All available Rebel Nebulon-B frigates participated in the Battle of Endor, playing a crucial role in the conflict. Sadly, the Redemption was destroyed by the Death Star's superlaser.
The frigates continued to be used by the New Republic, the successor to the Rebellion.
Variants

The Rebels modified some of their Nebulon-B frigates into medical vessels, which functioned as mobile treatment centers. They sacrificed weaponry and hangar space to accommodate treatment facilities, 15 bacta tanks, 745 beds, and other medical suites. The crew was adjusted to include 80 additional medical personnel and 30 medical droids (such as the 2-1B model). These ships were unable to carry any fighters, and their armament was reduced to 6 turbolasers (with computer-assisted targeting) and 8 laser cannons. Luke Skywalker received treatment for the injuries he suffered on Cloud City aboard the medical frigate Redemption.
Kuat Drive Yards eventually developed an enhanced iteration of the Nebulon-B, known as the Nebulon-B2. While generally similar, these models featured improved sublight speed, enhanced shields and hull armor, a reinforced connecting spar, and additional weaponry.
Following the Battle of Endor, Kuat Drive Yards built upon the success of the Nebulon-B with a new starship class, the 275-meter-long Corona-class frigate. Corona-class frigates were produced exclusively for the New Republic. As Corona frigates were not included in the New Republic's New Class Modernization Program, orders for these vessels remained limited. Some of them served in the Corellian Defense Force during the Second Galactic Civil War.
At least one EF76 was used as part of a secret refuge in 137 ABY. The criminal syndicate Black Sun operated a frigate of this type around this time, stationing it near Lun Rask's headquarters, a Vigo located above Kaer. Some were used during the Evacuation of Dac.
Behind the scenes
The Nebulon-B's design, created by Nilo Rodis-Jamero, was inspired by the appearance of an outboard motor.
In Star Wars: The Essential Guide to Vehicles, the entry for the Nebulon-B Frigate is mistakenly identified as a "Rebel Cruiser," which can lead to confusion with Mon Calamari Star Cruisers. Most sources typically refer to it as either "Nebulon-B Frigate" or "Escort Frigate."

There is some debate among fans regarding the Nebulon-B's stated fighter capacity. Computer games and deck plans in The Far Orbit Project depict a hangar situated in the forward hull, featuring a launch aperture on the starboard side. However, no such opening appears to be present on the model used in the films. Other depictions in computer games showcase starfighters docking and launching through an opening located in the narrow connection between the superstructure and the drive bay.
However, The Rebel Alliance Sourcebook, which seems to be the original source mentioning the Nebulon-B's starfighter capabilities, makes no mention of internal hangars. The text simply states: "The escort frigate has the capacity to carry up to two squadrons of starfighters into battle. In addition, the ship has docking fixtures to accommodate ships of up to medium freighter size" (p. 60). Given that The Empire Strikes Back displays the "docking fixtures" as external hardpoints on the spar connecting the prow superstructure and engines, it is possible that the fighters could also be transported on a rack along the spar, similar to Carrack-class cruisers, assault frigates, and FarStar.
Furthermore, some fans have speculated that certain Nebulon-Bs may have been equipped with an enclosed hangar bay positioned beneath the spar, filling the space between the forward keel and the engine block. Possibly added as aftermarket modifications, such hangars would allow them to carry fighters like X-wings more easily. Kalla's Stanchion, a ship that might belong to this subtype of the class, has appeared in Rebel Alliance hands in issue 22 of Star Wars: Empire. Although scaling extrapolations, when compared to snubfighters shown in the same panels, suggest a size considerably larger than the 300m-long Nebulon-B, the two designs are closely matched in appearance, and the size discrepancy may simply be a result of artistic license in the comic-book art. Footage from the game Star Wars: The Force Unleashed II shows the Nebulon-B frigate Salvation dwarfing the 65-meter Rogue Shadow by a significant margin.